From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9983C00454 for ; Wed, 11 Dec 2019 15:54:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 70BF3208C3 for ; Wed, 11 Dec 2019 15:54:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70BF3208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 03ADF6B32B7; Wed, 11 Dec 2019 10:54:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F2CB06B32B8; Wed, 11 Dec 2019 10:54:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E44016B32B9; Wed, 11 Dec 2019 10:54:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0201.hostedemail.com [216.40.44.201]) by kanga.kvack.org (Postfix) with ESMTP id CB5D16B32B7 for ; Wed, 11 Dec 2019 10:54:13 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 6DED32C14 for ; Wed, 11 Dec 2019 15:54:13 +0000 (UTC) X-FDA: 76253307186.30.road32_5efe9ad72630e X-HE-Tag: road32_5efe9ad72630e X-Filterd-Recvd-Size: 4762 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Wed, 11 Dec 2019 15:54:12 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A2A2B31B; Wed, 11 Dec 2019 07:54:11 -0800 (PST) Received: from [10.1.194.43] (e112269-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 88EAD3F52E; Wed, 11 Dec 2019 07:54:08 -0800 (PST) Subject: Re: [PATCH v16 13/25] mm: pagewalk: Don't lock PTEs for walk_page_range_novma() To: kbuild test robot Cc: Mark Rutland , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, "H. Peter Anvin" , Will Deacon , "Liang, Kan" , x86@kernel.org, Ingo Molnar , Arnd Bergmann , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, kbuild-all@lists.01.org, Ard Biesheuvel , linux-kernel@vger.kernel.org, James Morse , Andrew Morton References: <20191206135316.47703-14-steven.price@arm.com> <201912101842.KIXI4yCg%lkp@intel.com> From: Steven Price Message-ID: Date: Wed, 11 Dec 2019 15:54:06 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <201912101842.KIXI4yCg%lkp@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 10/12/2019 11:23, kbuild test robot wrote: > Hi Steven, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on linus/master] > [also build test WARNING on v5.5-rc1 next-20191209] > [cannot apply to arm64/for-next/core tip/x86/mm] > [if your patch is applied to the wrong git tree, please drop us a note to help > improve the system. BTW, we also suggest to use '--base' option to specify the > base tree in git format-patch, please see https://stackoverflow.com/a/37406982] > > url: https://github.com/0day-ci/linux/commits/Steven-Price/Generic-page-walk-and-ptdump/20191208-035831 > base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ad910e36da4ca3a1bd436989f632d062dda0c921 > reproduce: > # apt-get install sparse > # sparse version: v0.6.1-101-g82dee2e-dirty > make ARCH=x86_64 allmodconfig > make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' > > If you fix the issue, kindly add following tag > Reported-by: kbuild test robot > > > sparse warnings: (new ones prefixed by >>) > >>> include/linux/spinlock.h:378:9: sparse: sparse: context imbalance in 'walk_pte_range' - unexpected unlock I believe this is a false positive (although the trace here is useless). This patch adds a conditional lock/unlock: pte = walk->no_vma ? pte_offset_map(pmd, addr) : pte_offset_map_lock(walk->mm, pmd, addr, &ptl); ... if (!walk->no_vma) spin_unlock(ptl); pte_unmap(pte); I'm not sure how to match sparse happy about that. Is the only option to have two versions of the walk_pte_range() function? One which takes the lock and one which doesn't. Steve > vim +/walk_pte_range +378 include/linux/spinlock.h > > c2f21ce2e31286 Thomas Gleixner 2009-12-02 375 > 3490565b633c70 Denys Vlasenko 2015-07-13 376 static __always_inline void spin_unlock(spinlock_t *lock) > c2f21ce2e31286 Thomas Gleixner 2009-12-02 377 { > c2f21ce2e31286 Thomas Gleixner 2009-12-02 @378 raw_spin_unlock(&lock->rlock); > c2f21ce2e31286 Thomas Gleixner 2009-12-02 379 } > c2f21ce2e31286 Thomas Gleixner 2009-12-02 380 > > :::::: The code at line 378 was first introduced by commit > :::::: c2f21ce2e31286a0a32f8da0a7856e9ca1122ef3 locking: Implement new raw_spinlock > > :::::: TO: Thomas Gleixner > :::::: CC: Thomas Gleixner > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >